Regulation of appetite occurs through the following factors:

1. Hypothalamus: 

1. Feeding center, the lateral hypothalamus.
2. Satiety center, ventromedial nucleus.                

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2. Hormones :

a.       Cholecystokinin: ↓ appetite.

b.      Calcitonin: ↓ appetite. Secreted from the Thyroid Gland

3. Mechanical Distention: Increase in stomach size due to food → ↓ Appetite

4. Glucostatic hypothesis: Through the glucose balance in the body.

5. Lipostatic hypothesis : Through the lipid balance in the body.

6. Temperature Regulation, Increase in temp. = Decrease in appetite.

Regulation of the thirst occurs through the following factors:

1. Extra cellular fluid volume: through the renin-angiotensin system & cardiac -vascular baroreceptors.

2. Plasma osmolality:  ↑ Plasma osmotic pressure → simulation of osmoreceptors in ant. Hypothalamus promoting drinking.

3. Other factors :

                                                               i.      Dryness of the pharyngeal mucosa → Thirst

                                                             ii.      Mechanical stimulation of the pharynx and stomach (stretching) → inhibits drinking.